Glyoxylate Sulfonyl Hydrazone Enables a Scalable Approach to Reformatsky-Type Products from Aliphatic Alcohols via Photocatalytic HAT

Herein, a commercially available ethyl glyoxylate sulfonyl hydrazone engages in a photocatalytic hydrogen atom transfer mechanism with aliphatic alcohols, delivering β-hydroxy ester compounds without relying on transition metal chemistry. The protocol operates under mild conditions in green solvents and is readily scalable up to 25 g. Mechanistic studies identified the initial HAT as the rate-limiting step in the photocatalytic transformation and provided further insights into the base-promoted cleavage of the sulfonyl hydrazide intermediate.